To focus on the acquisition and analysis of neuroimaging data on Baltimore Longitudinal Study of Aging (BLSA) participants. This project will continue to provide important information for researchers and clinicians on age changes in brain structure and function, their associations with cognitive change, and factors that modulate these associations, including risk factors for cognitive decline and Alzheimer's disease. A number of recent studies indicate that structural and functional longitudinal changes in specific temporal lobe regions predict cognitive impairment and Alzheimer's disease, but there are few studies that provide data on longitudinal changes in regions throughout the brain and for both gray and white matter. Using new imaging methods, we will continue to investigate the neurobiological basis of cognitive impairment and dementia. In addition to continued volumetric studies ofbrain aging, in vivo measurement ofvascular changes and amyloid deposition shall be emphasized in the next phase of this research program. Recent evidence indicates possible synergistic effects of vascular changes and Alzheimer's pathology on the development of dementia. As approximately half of the current sample aged 55 and older is enrolled in the BLSA autopsy program, in vivo imaging changes will be validated against neuropathological findings. In addition to the continued investigation of older adults, younger individuals in the BLSA will be recruited for MR imaging studies to provide information on structural brain changes throughout the adult lifespan. Through the use of the existing physical and psychological data for BLSA participants, this project will provide unique insights into our understanding ofpredictors of individual differences in the rate ofneuroanatomic, neurophysiologic and cognitive aging.This neuroimaging data will also provide important normative data, including the frequency and extent ofbrain abnormalities in community-dwelling individuals, from which to evaluate pathological